We are investigating whether loss of Base Excision Repair (BER) promotes accelerated age-related remodeling in the heart and the vascular system. The mechanical properties of the vascular system are controlled by its microarchitecture. The largest artery is the aorta, which is composed of four main components: collagen fibrils, elastic fibers, vascular smooth muscle (VSMC) and endothelial cells and these are organized into three layers known as the tunica intima, tunica media and tunica adventitia. In the aorta, there is progressive stiffening with advancing age, but the molecular mechanism responsible for this phenomenon is not well understood. An age comparison between WT and PolB HT mice will be undertaken to interrogate the cardiovasculature in this mouse model and determine if there are any major anatomical differences between the WT and the PolB HT mice.